The first vulnerability fixed is the address bar spoofing bug which we reported on back in March. David Vieira-Kurz of MajorSecurity discovered an address bar spoofing vulnerability in WebKit that allows an attacker to manipulate the address bar in the browser and take the user to a malicious site with a fake (but genuine looking) URL showing. The vulnerability is caused due to an error in the handling of URLs when using javascript’s window.open() method.

The next vulnerability fixed by Apple is the cross-site scripting issue found by Sergey Glazunov that earned him $60,000 from Google under its Pwnium: rewards for exploits contest. Details of the exact nature of Sergey’s exploit are still unavailable but it is known that WebKit doesn’t properly handle history navigation, which allows remote attackers to execute arbitrary code by leveraging a “Universal XSS (UXSS)” issue.

The final fix is also shrouded in mystery. CVE-2012-0672, which was found by Adam Barth and Abhishek Arya of the Google Chrome Security Team, is a memory corruption issue in WebKit that, if exploited, would allow an attacker to create a malicious website that could crash Safari or execute arbitrary code. However that is all that is known!